Fourier Patents (Class 708/403)
  • Patent number: 6021423
    Abstract: A method using replication of distributed arithmetic logic circuits and recursive interpolation of reduced angular increments of sine and cosine sum constants in logic look-up tables permits the computation of vector rotation and large FFTs in an efficient-parallel fashion within a unitary field programmable gate array chip, without off-chip memory for storing constants.
    Type: Grant
    Filed: September 26, 1997
    Date of Patent: February 1, 2000
    Assignee: Xilinx, Inc.
    Inventors: Sudip K. Nag, Hare K. Verma
  • Patent number: 5991787
    Abstract: A method for computing a decimation-in-time Fast Fourier Transform of a sample is provided, the method including inputting first 2B-bit values representing the sample into a radix-4 first section of the decimation-in-time Fast Fourier Transform and performing first complex 2B-bit integer additions and subtractions on the first 2B-bit values to form second 2B-bit values, without performing a multiplication. The method also includes rounding the second 2B-bit values to form B-bit values output from the radix-4 first section of the decimation-in-time Fast Fourier Transform.
    Type: Grant
    Filed: December 31, 1997
    Date of Patent: November 23, 1999
    Assignee: Intel Corporation
    Inventors: James Abel, Michael A. Julier